1. Field of the Invention
The invention relates generally to chemical compositions and methods for using same, for regulating the growth of plants. More particularly the invention pertains to a liquid solution formed from a mixture of chlorocholine chloride, poly[oxyethylene(dimethyliminioethylene(dimethyliminio)ethylene]dichloride, choline chloride, and an inert carrier, which is spray applied to crop plants at selective times and in selective concentrations to improve crop yield.
2. Description of the Prior Art
Plant growth regulators are well known in the prior art. For example, in U.S. Pat. No. 3,905,798, the application of salts of cyclic nitrogenous compounds to cotton plants for controlling their growth, is described. German Patent 28 15 443 teaches growth regulation of cotton plants through the aerial application of N, N-dimethylpiperidinium chloride, another cyclic nitrogenous compound. Yet another compound, designed to regulate the growth of cotton plants, is described in U.S. Pat. No. 4,439,224. This compound is made from a mixture of N,N-dimethylpiperidinium chloride (hereinafter xe2x80x9cPIXxe2x80x9d), and poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene] chloride.
When cyclic nitrogenous compounds are applied to cotton plants under stress, it is common for the plants to be shocked into xe2x80x9cCut-Outxe2x80x9d. This term is recognized in the industry as describing the condition of a cotton plant when it stops all vegetative and reproductive growth. If this condition is induced by chemical treatment or occurs naturally, at some point early in the season prior to the plant""s normal physiological timing, dramatic crop yield reductions will occur.
The non-cyclic nitrogenous salt, 2-chloroethyltrimethylammonium chloride, also known more commonly as Chlorocholine Chloride and sold under the trademark CYCOCEL, has also been used to regulate the growth of cotton and cereal plants. In fact, Chlorocholine Chloride (xe2x80x9cCCCxe2x80x9d) is well established as the standard plant growth control product in cereal production. The cyclic nitrogenous compound PIX is disfavored to treat cereal plants, as it is not as effective to control growth in such plants.
However, with respect to cotton plants, Chlorocholine Chloride is not accepted as the best commercial product. It is recognized that CCC produces unpredictable results and exhibits a high risk of reducing the crop yield of cotton plants, when compared to PIX. With cotton plants, Chlorocholine Chloride tends to induce the above-described Cut-Out problem. For example, the commercial product STABILIN, containing 38.4% chlorocholine chloride, is registered by the government in Greece for use on cotton to control plant growth. The recommended application rate for STABILIN is 40 grams per hectare, applied twice, with a first application made 45 days after germination followed by a second application 14 days later. This high rate of CCC application, totaling 80 grams per hectare, provides controlled growth of the cotton plant but is accompanied by an undesirable decrease in crop yield.
Another generally recognized recommendation in the industry is to apply Chlorocholine Chloride on cotton at a rate of 400 to 2000 grams per hectare, about 75 to 90 days after seeding. These rates for CCC application are significantly higher than the suggested use rates of 25 to 50 grams per hectare, for the cyclic nitrogenous product, N, N-dimethylpiperidinium chloride. Unfortunately, the high application rates of CCC increase the probability of inducing Cut-Out and attendant crop yield reduction.
A plant growth regulator is disclosed which is particularly effective for use with cotton plants. The plant growth regulator is a composition, preferably in the form of a liquid solution, made by mixing together chlorocholine chloride, poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene]dichloride, choline chloride, and an inert carrier, such as water.
Selected inorganic salts are preferably added to the liquid solution, to improve its performance as a growth regulator. For example, when calcium and zinc ions are added to the solution, the harshness of the CCC is buffered and crop retention by the plant is improved. Calcium ions increase the efficacy of CCC, allowing lower application rates than would otherwise be required to control plant growth effectively. Zinc ions promote the synthesis of auxin, and enhance the plant""s ability to maintain fruit set and boll retention.
In a first application, the liquid solution is spray-applied to the foliage of young subject plants, well prior to crop harvest. The timing of the application and the concentration of the active ingredients used are such that undesirable rank growth is inhibited, while fruit-setting and fruit growth are encouraged. Cut-Out of the plants is avoided, as the composition of the solution uses much less CCC, yet remains efficacious.
A second application of the liquid solution may also be made, just prior to harvest. The formulation of the solution used in this second application is different. The inorganic salts which are preferred for use in the first application, are not included. This modification is made as the addition of new fruit to the plants is undesirable just before harvest. In addition, a more concentrated form of the solution is used to induce Cut-Out of the plants. Accordingly, at this stage in the plant""s development, the formulation of the solution is tailored to accelerate plant maturity and condition the plants for defoliation or desiccation.